ignition-math7: depend on ignition-utils1 (#1735)
ignition-math7: depend on ignition-utils1 (#1735)

Signed-off-by: Michael Carroll <17b9e1c64588c7fa6419b4d29dc1f4426279ba01@openrobotics.org>
Co-authored-by: Steve Peters <19cdd629ec3b4ea4663c77a4169548f370fdc02f@openrobotics.org>
osrf/homebrew-simulation,scpeters/homebrew-simulation